Caption: Short-finned pilot whales (Globicephala macrorhynchus) of differing sizes. Whales and dolphins dive to feed, coming to the surface for air. The short-finned pilot whale, which is found throughout the world's temperate and tropical waters, is actually a large dolphin. It can be between 4 and 6 metres in length, and feeds on fish, squid and octopus. Photographed in the Canary Islands.